ensure maintenance is carried out by a competent person (someone who has the necessary skills, knowledge and experience to carry out the work safely) 1  maintain plant and equipment regularly â use the manufacturerâs maintenance instructions as a guide, particularly if there are safety-critical features.
HDPE (High Density Polyethylene). 3/4 HDPE will cost about $45.00 for 100' ($0.45/ft), so depending on the amount required can be much cheaper than the previous options. HDPE is used by many municipalities as water supply lines, so it has been tried and tested in underground applications.
1 Its cost, on average, is $650, compared to $400 for take-home trays and under $100 for over-the-counter bleaching trays or whitening strips. 2  Results can be unpredictable, depending on factors such as age, heredity and the type of staining that is present.  In-office bleaching is not a permanent solution.